OSCANIUS. 39 



around them, which their complex stomachs seem well cal- 

 culated to digest, and they are very slow in their move- 

 ments. 



Species of Pleurobranchus. 



aurantiacus, Eisso. ocellatus, Chiaje. 



Blaiuvillii, Lesson. Patagonicus, D'Orb. 



brevifrons, Phil. perforatus, Phil. 



citrinus, Rupp. plumula, Mont. 



cornutus, Quoy and Gaim. Peronii, Cuv. 



De Haanii, Cantr. punctatus, Quoy and Gaim. 



Forskalii, Chiaje. stellatus, Risso. 



niamillatus, Quoy and Gaim. tuberculatus, Chiaje. 

 oblongus, Savigny. 



Genus OSCANIUS, Leach. 



Tentacles dorsal, irregular, ear-like; labial processes 

 broad and triangular. Mantle smaller than the foot, en- 

 tirely concealing the head, fissured in front and behind. 

 Foot large, thin, foliaceous. 



Shell internal, large, thin, membranous, flattened, 

 orbicular, with a postical apex. 



Ex. O. dilatipes, H. and A. Adams, pi. 60, fig. 5, 5, a. 

 Shell, O. membranaceus, Montagu, fig. 5, b. 



The Oscanius we have figured is pale red, with deep, 

 red-brown, depressed lines, and light pink tubercles sur- 

 rounded by dark red-brown zones ; the foot is flesh- 

 coloured, with faint concentric stria?. (In spirits in 

 Mr. Cuming's Collection.) 



Species of Oscanius. 



dilatipes, H. and A. Adams. membranaceus, Mont. 



Lesueurii, Blainv. 



